Sand-heating apparatus for building purposes



- 1,631,699 June 1927- F. SELMER SAND HEATING APPARATUS FOR BUILDING PURPOSES Filed Oct. 30, 19 24 v [Wen/0r 8 ,9 Pie/men Patented June 7, 1927.

Ul iiT-El) STATES FREDBIK SELMER, OF CHRISTIANIA, NORWAY.

SAND-HEATING APPARATUS FOR BUILDING- PURPOSES.

Application filed October 30,1924, Serial No. 748,961, and in Norway November 9, 1923.

My invention relates to a sand heating apparatus for building purposes.

When concrete casting and masonry has to be done in low ten'iperatures after the frost has set in, it is necessary to have the materials (sand and water) heated before use.

It is usual to heat the sand and water separately, the sand being heated by means of sand heating ovens and the water in separate receptacles (pots) on a fireplace. The sand heating ovens hitherto known are liable to be overheated, and under such conditions they are apt to be pressed together by the weight of the overlying sand and destroyed.

The object of my invention is to provide a combined sand heating and water heating apparatus, arranged in such a manner that the outer shellof the apparatus is supported by a system of water tubes through which is passed the water to be heated. In this man ner the tubes, in which the water is heated serve simultaneously as a skeleton and inte-- rior protection for the body or outer shell of the sand heating apparatus.

This apparatus may be of any suitable cross section, cylindrical, triangular or the like, and may be arranged at will horizontally, vertically, or at an angle, and the water-tubes arranged therein may be arranged in form of a spiral, zigzag-shaped, in form of a grate or the like.

In the following the invention shall be explained with reference to the accompanying drawings illustrating several exeoutional forms of the apparatus.

Figs. 1 and 2 are, respectively, a longitudinal section and a cross section on line 2-2, Fig. 1, of a cylindrical sand and water heating apparatus.

Fig. 3 is a cross section of'a substantially triangular apparatus.

Fig. t is a corresponding cross section of a roof-shaped apparatus,

Fig. 5 is a longitudinal section of a further modification, Fig. 6 is a tront'view of the front wall of this apparatus and Fig. 7 is a cross sectional view on line 77, Fig. 6, illustrating also the circulation tank combined with the tubing of the apparatus.

In the executional form illustrated in Figs. 1 and 2, 1 is the outer, cylindrical shell of the sand heating apparatus, 2 is the fireplace, provided with a grate 3, from which the combustion gases pass to the stack 4.

According to my invention the water to be at5 in a spiral-shaped water tube 6 arthat it is in contact with its inner wall throughout and serves as alreinforcing skeleton for-the same. 7

As will be seen from Fig. 1 thespirals may preferably be arranged closer together in the partof the apparatus that is subjected to the strongest heat, this part of the apparatus being most in need of cooling.

Fig. 3 illustrates a cross section of an apparatus having a roofshaped shell 1, open at the base, the water tube 6 being here arranged in a triangular helix forming a roofshaped skeleton supporting the shell 1.

The modification illustrated in the cross sectional view Fig. 4 only differs from the form illustrated in Figs. 1 and 2 therein that the shell 1 and its supporting tubes are arranged'with a substantially triangular cross section.

In the executional forms diagrammatically illustrated in the preceding figures the emptying of the water tubes in order to avoid freezing of the tubes when the apparatus is out of action at night, presents certain difiiculties, it being necessary to have the water blown out by steam or air pressure. In the executional form illustrated in Figs. 5 to 7 these difliculties are avoided, the arrangement being such as to enable the letting off of the water in the water tubing simply by opening a cook or tap.

The tubing in this apparatus is composed of a longitudinal main tube 7 placed along the ridge of the roofshaped shell 6, the lat ter having a cross section resembling a gothic arch, similar longitudinal tubes 8 are placed along the lower edges of the shell 6; the tubes 7 and 8 are interconnected by aid of a number of rib-shaped tubes 9, the form of said tubes conforming with the cross sectional curve of the shell 6.

The two tubes 8 may also be interconnected through horizontal tubes 10, a number of which may be placed so close to each other as to form a waterfilled grate.

The two tubes 8 protrude beyond the front wall 11 (Fig. 6) of the apparatus, being provided with cocks or couplings 12, one of which may eventually be arranged to connect the water tube system with a conduit of water under pressure (not shown).

In Fig. 7 is illustrated a circulation tank 13, connected to thetube 7 by a tube 14, and

ranged within the shell 1 in such manner to the tubes 8 a tube 15, thereby ensuring a cirzculation of the Water heated in the tubes 7, 8 and 9. The heated Water to be used for slaking or casting is tapped from the cook 16 of tank. This cook" 16 is placed at such a level relatively to the. port. 17 through which connection is had with the tube system oi; theheatin apparatus, that the level in the tank will always cover the port-17*, thus ensuringa constant circulation of the Water; through the, tube system of the Waterheate As will. be: seen the entire tube system of the sand heater maybe emptied by opening oneor both of the cocks 12. V1 hen both of these cocks are closed the; water will circulate continuously through the tank and the Water tube system.

Claim A combined sand" anol' Water heating apparatus comprising ashell, a, fireplace, a water tubing including arch forming portions arranged, in direct supportin and? heat interchanging relation Withsaid shell, about said fireplace, and means for circulatingwater through saiditubing,

In testimony thatl claim the toregoing as my invention, I have signed.- my name.

FREDRIK sELMER. 

